Man pages matching name datetime::calendar::discordian in section 3pm:

DateTime::Calendar::Discordian.3pm.en	debian 10 / libdatetime-calendar-discordian-perl
DateTime::Calendar::Discordian.3pm.en	debian 11 / libdatetime-calendar-discordian-perl
DateTime::Calendar::Discordian.3pm.en	debian 12 / libdatetime-calendar-discordian-perl